if the speakers can genuinely handle 50W, then 400/500W per channel and lock down the controls / add a limiter so folk can’t grossly overpower the speakers.

It is better to have more power in reserve than drive a smaller amp into clipping which will also destroy the speakers.

Or rather than this complex series/parallel array, use a 100V system with individual transformers in speakers so you can set each speakers power demand as required.

OK these speakers might be slightly more expensive per unit but you would save a few rupees in cabling, you can use “telephone cable CW1308 or similar”.

I hope this is not your college homework question, as firstly you should be doing that yourself, and secondly if it is your prof hasn’t given the best description of the system!

In any case the most info you can give helps. Most sound system advice here relates to transportable systems for indoor and outdoor music events in European countries where music with a strong sound and loud bass is preferred and the loudspeakers are usually upon the stage where DJ’s or performers also are situated.

but from your description this might even be a general purpose system for a hall rather than simply for a loud discotheque type installation so it could be anything from a music concert to a talk by the local fishermen, and thus the loudspeakers are distributed throughout the hall rather than at one point. So cable losses would become significant, and the complex series/parallel set up could be miswired in many ways. But if you use 100V line then it is far simpler. you may also find that it is better to use mono than stereo.

In this case I would have a meeting with your association and try and get them to fund the 100V equipment right from the start. As that way you could get a 300W 100V line output amp, rather than use the more expensive cable you can use the cheaper cable used for telephones or smaller speakers, and the speakers with transformers and the volume control tappings.

in the UK we have a company called CPC / Farnell (it might be called Element 14 in your country or one near you) which sells lots of affordable PA kit, and many of the loudspeakers are good for both speech and music.

That way you can use this to move some speakers to the corner and also adjust the levels of these, avoiding the echo problems and giving you leeway to relocate things if they are not quite in the “right place”. my extended family come from Malaysia which is a multicultural, multi faith society (and also makes a lot of electronic equipment) and the current best practice there is to use a “Western” approach to sound systems in all places of worship and go for best sound quality for both speech and music.

For amplifiers you really should get a professional amp rather than use the “hi fi” amps. The hi fi amps are made to listen to music in your house and not always as robust as the PA amplifiers.

The inter -m is a good one as it would work with either low impedance loudspeakers or 100V. Also it has the phono line output so you can have your second amp and two speakers on the stage (which will need independent volume control to avoid feedback).

Inter-M PA-6000A Amplifier

I could not find any info on the speakers. bear in mind you can buy the 100V transformers separately and build them into the speaker cabinets.

Do you have suppliers of this equipment locally, or will you have to import it from another country?

I believe Mauritius is hot, so you will need one with good fans/ventilation and that will not generate excessive heat when switched on for a long period.

Is the electricity supply in the hall good and reliable? does it have airconditioning and other big appliances connected to it? (you have to be careful of these as they can put unwanted noise into your sound system).

@Shadows 527263 wrote:

General Lighting

Your Para 1: What is it If we use for this session an Hi-Fi amp and in few month we choice an PRO amp PA with 100v ?

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you might be able to do this for a smaller scale system (perhaps with less speakers), but must be careful the amp is not made to produce too much power/gets too hot. Often there is not much price difference between a hi fi amp and a smaller PA amp anyway.

Also you need to bear in mind what the sound sources will be. Usually with religious services there are one or more microphones, and perhaps recorded sound from another source, often these are used together. so you will need an amplifier with a mixer section. hence the PA-6000 amp would be ideal as it has this built in. If your religious leaders are not sound engineers they could find other equipment too difficult to use, whereas a hi fi amp even with microphone inputs (many Asian ones have these as karaoke is popular) might not have enough mic inputs, and they will be “unbalanced” and thus will let noise in.

Your Para 2: I didn’t knew that the PHONO output can be used as pre-amp, So good ! I’ll keep in mind PA-6000A amp.

be careful here that “phono” is a term used for the type of connector (RCA connector is another word of it) but also a type of input (for gramophone turntables). what you want from an amplifier is a “Line Output” or “Record Output” which is the output of the pre amp.

Your Para 3: I got two choices of speakers:-
FIRST type 8 ohms 50 watts MAKE Rayden YD 103 and
SECOND type 4- 8 ohms 50-100 watts.MAKE Rayden R 103 Japan
Yes for seperate transfo, I’ll be back soon.

The only Rayden loudspeakers I could find from Japan are the sort sold for motor cars. Do they come in enclosures, or will a local carpenter be building them?

Your Para 5: Already have a local fan, thanks for reminder….The system will stay on from 9 to 16hr for three days.
Your Para 6: Electricity study 220 volts can be interupt without notice from electrical company !
I prepare to insert a UPS in circuit just as standby, with additional batteries in stock !!
No Air Cond. just 4 ceiling fans and Fluo. lighting
What do you think about capacitor on mains 220v just to reduce incoming noise ?

most modern sound equipment already contains the capacitor. Putting another extra mains filter in the supply needs to be done properly by a qualified electrician or it can be very dangerous, as if miswired it will make all the metal of the equipment alive to the mains electricity.

Quote:

How you checked Thread 5 for size of wire:- 50/0.25mm X 25 meters from amp output to a group speakers extended with 30/0.25 to last speaker in this group which length is 11meters. Repeat same for the second channel.
With these size of wire I try to keep the load as 8 ohms as possible. Thus avoiding volt drop, I suppose !

You should get away with this but as cheeseweasel said be careful about the wiring. (also make sure that it and any junction boxes used cannot be confused with 220V wiring for the building!)

That looks like it should do the job for your organisation. it is very similar to the old British way of setting up sound systems in temporary structures especially church halls, youth clubs etc. In most faith groups (and even at Western style rave parties held in outdoors) it is commonplace to collect donations for the upkeep of a sound system at the gatherings…..

Make sure your voltage stabiliser is connected correctly to the mains protective earth for your building, and that this earth is good and robust throughout the building (any exposed metal in the building must be connected to it). This could be a metal spike sunk deep into the ground, or the metal outer covering of the electricity cable. Your electric power company should be able to tell you this, or the electricans who wired up your hall. (in most countries such installations must be tested for safety every 5 years and notes kept of this).

I forgot to say add that I do use a UPS on my home system as even though the UK is supposed to be a developed Western country, global energy shortages and market fluctuations mean that the voltage (supposedly 230V) can vary wildly especially over weekends, and power cuts for a few seconds are common. This is enough to cause many problems with computers and other digital electronics. Originally I bought the UPS for my computers and a telephone exchange and IP network equipment that is in the bottom stairwell of my house (so I can work from home) but I found it made the sound quality of my audio equipment better by isolating the mains power from other surges, sags and noise. if your local electricity supply is very intermittent and you expect to be using UPS battery power quite often, a pure sine wave inverter in the UPS is desirable as that means there will be better quality power when you have to use the UPS for your main power source.

@johnjamesss 536414 wrote:

Sorry to jumping in on someone else’s thread but what’s the best configuration for hall speakers?

Depends on the hall size/shape, how loud the speakers are etc.